Insulation resistance testing with electronic equipment between L-N connected together and earth.
Switch mode power supplies have EMC capacitors between L - N - E.
However, when you test for IR you are using DC. Capacitors block DC.
What is there in some electronic equipment that allows a DC current to flow from L-N to earth?
This also happens in RCBOs that have a functional earth tail.
Also, not all switch mode power supplies have EMC capacitors. Plug-in ones have no earth. If they can be made without the earth, and therefore omit the EMC capacitor to earth, why on earth (he he) can't they all be made that way? (I have a feeling the answer to that is that there is provision to omit EMC from small items).
Switch mode power supplies have EMC capacitors between L - N - E.
However, when you test for IR you are using DC. Capacitors block DC.
What is there in some electronic equipment that allows a DC current to flow from L-N to earth?
This also happens in RCBOs that have a functional earth tail.
Also, not all switch mode power supplies have EMC capacitors. Plug-in ones have no earth. If they can be made without the earth, and therefore omit the EMC capacitor to earth, why on earth (he he) can't they all be made that way? (I have a feeling the answer to that is that there is provision to omit EMC from small items).
